Recent Topics
2005 Volvo S40 2.4i - Optimal Oil Choice?
by mgm7890
27 minutes 5 seconds ago
Something for a quiet Saturday, vapors...
by OneEyeJack
52 minutes 1 second ago
Ford guys: Crown Vic windshield washer not working
by Jimmy9190
Today at 12:08 PM
Very cold outside, vehicle sitting for a few day's
by 07titan
Today at 11:26 AM
compression fittings and fuel starvation
by eljefino
Today at 10:47 AM
Anyone here make a homemade jump starter pack?
by skyactiv
Today at 10:31 AM
API *SL* Oil Still on Shelf
by CrackyWainwright
Today at 10:17 AM
Jeep "shudders" at 35-40 mph
by Joe_Power
Today at 09:27 AM
How Often to Drain and Refill AT's?
by Gebo
Today at 09:18 AM
Gas water heaters
by spasm3
Today at 08:59 AM
Woman killed by flying manhole cover in Boston
by Mr Nice
Today at 08:56 AM
Fresh oil change - dipstick smells like exhaust
by ragtophardtop
Today at 08:50 AM
Newest Members
wdleighton1, RTS, jhmed80, engus, Rob_Pol
56902 Registered Users
Who's Online
85 registered (Branson304, bbhero, BrocLuno, 90crvtec, BMOC, Boss302fan, 9 invisible), 1870 Guests and 100 Spiders online.
Key: Admin, Global Mod, Mod
Forum Stats
56902 Members
66 Forums
244645 Topics
3985068 Posts

Max Online: 2862 @ 07/07/14 03:10 PM
Donate to BITOG
Topic Options
#2417308 - 10/26/11 07:50 PM 1998 z71 front &rear diff's
Jaybird79 Offline


Registered: 11/01/10
Posts: 7
Loc: Illinois
Hi does anybody know if i can run Mobil 1 75w90 in both the front and rear differentials in this truck? Also do i need to put any LS additive in either one,it does have the Eaton G80 in the rear.

Top
#2418125 - 10/27/11 05:45 PM Re: 1998 z71 front &rear diff's [Re: Jaybird79]
artificialist Offline


Registered: 09/23/07
Posts: 7858
Loc: Florida
What does your owner's manual say your truck needs?
_________________________
2010 Lancer Ralliart Sportback

Top
#2418283 - 10/27/11 08:40 PM Re: 1998 z71 front &rear diff's [Re: Jaybird79]
Fazzone Offline


Registered: 08/17/09
Posts: 104
Loc: Mondovi Wisconsin
Yes, you should be fine. I had no issues in my last truck('98 GMC 1500 Z71) running it. As far as the LS additive, mine didn't need it, but I don't recall specifically which rear end was in it. The manual specs call for conventional in the front, but if you want to spend the extra $ go for it.
_________________________
2012 GMC 2500 HD

Top
#2418285 - 10/27/11 08:40 PM Re: 1998 z71 front &rear diff's [Re: Jaybird79]
Jaybird79 Offline


Registered: 11/01/10
Posts: 7
Loc: Illinois
SAE 80w90 GL-5 gear oil front and rear.

Top
#2418463 - 10/28/11 05:55 AM Re: 1998 z71 front &rear diff's [Re: Jaybird79]
NHHEMI Offline


Registered: 07/06/07
Posts: 6054
Loc: NH
Originally Posted By: Jaybird79
Hi does anybody know if i can run Mobil 1 75w90 in both the front and rear differentials in this truck? Also do i need to put any LS additive in either one,it does have the Eaton G80 in the rear.


You can run 75W90 synthetic in both and it would be an upgrade. No LS additive required with the G80 but if the fluid you select has it don't worry. It will still work fine.
_________________________
Proud user of Royal Purple products thumbsup

Top
#2418503 - 10/28/11 07:49 AM Re: 1998 z71 front &rear diff's [Re: Jaybird79]
Jaybird79 Offline


Registered: 11/01/10
Posts: 7
Loc: Illinois
Thanks NHHEMI, just wanted make sure it would be okay. I can get the mobil 1 for about $4.00 a qt at AAP so I thought why not upgrade.

Top
#2419234 - 10/28/11 09:25 PM Re: 1998 z71 front &rear diff's [Re: Jaybird79]
wtd Offline


Registered: 06/25/02
Posts: 1491
Loc: southwest Mo.
I run shell coventional 80W-90 gear oil in my 98 Z71 but used to run Mobil 1 in both diffs. It might just be a coincidence but I had to have my rear end rebuilt at 75,000 miles with hardly any towing or hauling. After that I went back to conventional and now at 120,000 miles, no problems. I first started hearing noises at about 55,000 miles but could not figure out what it was and finally had it looked at professionally which ended up with the repair. Others have had good luck with it so for that price you might as well try it.

Wayne
_________________________
2014 Mustang GT
1998 Chevy K3500
1998 Chevy K1500
(2) 1992 Cavaliers
1970 Monte Carlo

Top